With the proliferation of wireless communication systems, compatible handheld communication devices are becoming more prevalent, as well as advanced. Whereas in the past such handheld communication devices were typically limited to either voice transmission (cell phones) or text transmission (pagers and PDAs), today's consumer often demands a multifunctional device capable of performing both types of transmissions, including even sending and receiving e-mail. Furthermore, these higher-performance devices can also be capable of sending and receiving other types of data including that which allows the viewing and use of Internet websites. These higher level functionalities necessarily require greater user interaction with the devices through included user interfaces (UIs) which may have originally been designed to accommodate making and receiving telephone calls and sending messages over a related Short Messaging Service (SMS). As might be expected, suppliers of such mobile communication devices and the related service providers are anxious to meet these customer requirements, but the demands of these more advanced functionalities have in many circumstances rendered the traditional user interfaces unsatisfactory, a situation that has caused designers to have to improve the UIs through which users input information and control these sophisticated operations.
Keyboards are used on many handheld devices, including telephones and mobile communication devices. The size of keyboards has been reduced over the years, as newer, smaller devices have become popular. Cell phones, for example, are now sized to fit in one's pocket or the palm of the hand. As the size of the devices has decreased, the more important it has become to utilize the entire keyboard surface as efficiently as possible.
For example, many keyboards on mobile devices have an input device for navigation through the graphical user interface. These interfaces include such devices as trackballs and rotating wheels which can be used to effect movement of a cursor or pointer, or to scroll up, down and about a displayed page. These navigation devices often occupy a relatively large amount of space on the incorporating mobile device. Because the navigation device is frequently used and often requires fine control, a lower end size limitation will normally be observed by device designers. To accommodate such larger, more convenient navigation devices on the housing of the mobile device, the amount of space that is available for the keys of the keyboard is correspondingly reduced if the keyboard and navigational device are proximately located to one another. It is important to make the keys upon the keyboard conducive for typing with respect to both functionality and accessibility. Specifically, increasing a key's functionality serves the user in that it makes the device more versatile if more easily, engaged in multiple applications. But, given the physical constraints of a handheld mobile device, increasing key functionality upon the keyboard without considering its affect upon key accessibility can actually make the device less conducive for typing. Simply put, a versatile device is truly versatile only if the user can make use of it. Thus, in addition to functionality, the user must feel the device is accessible such that minimal typing obstacles arise during normal course of use. To accomplish this goal, the keyboard must be more discernable to the user, both visually and tactilely. For example, a keyboard that is typing-conducive leads to lesser instances of unintended actuation of the keys. The elongate raised rails prevent keys from being unintentionally depressed when a neighboring key is actuated. As the user's digits teeter upon the elongate raised rail, an intended key may be simultaneously actuated with a portion of the user's digit not already resting upon the elongate raised rail. Since the entire digit need not be specifically moved to a particular key, the likelihood of unintended actuation is thereby reduced. Thus, it is beneficial to visually and tactilely distinguish the keyboard.